Lubricant additive and composition containing same



vuct with at least a sufiloient amount of an 'pound to neutralize the reaction product and then reacting United States Patent 3,1tl23959 LUBRECANT ADDETEVE AND (IGMEPGSHTHEN C(ENTAHNHIIG dAME Donald L. Klass, Barrington, 111., and Roger W. Watson, Highland, Inch, assignors to Standard 0i! Company, Chicago, Ill., a corporation at Indiana N0 Drawing. Filed Dec. 8, 1953, Ser. No. 778,583 1t) Qlaims. (Cl. 25232.'7)

This invention relates to additive compositions for use in lubricating oils, the use of such additive compositions, and improved lubricating compositions containing such additive compositions and intended for use in internal combustion engines such as diesel engines and automobile engines. More particularly the invention relates to additive compositions which impart detergency and anti-rust properties to lubricating oils and suppress excess varnish formation and octane requirement increase when used in lubricating oils.

Straight petroleum lubrican s are effective within certain defined limits of engine operating conditions and when these limits are exceeded, such lubricants frequently fail to give the desired periormance demanded of them. Since, in modern engines designed to give increased performance, these limits are frequently exceeded, the use of straight mineral oils as lubricants produce undesirable conditions within the engine; thus varnish formation, corrosion, preignition and octane requirement are all excessive in modern engines using mineral oils alone.

It is an object of the present invention to provide a new composition for use as a lubricant additive. it is another object to provide a lubricating oil additive composition which imparts detergency, anti-varnish formation and anti-rust properties to a lubricating oil. Other objects and advantages of our present invention will be apparent from the descriptions and examples set out below.

We have discovered that a hydrolyzed phosphorus sulfide-hydrocarbon reaction product may be reacted with an amine compound and a borophosphoric acid to form a new composition of matter with desirable characteristics for use as an additive composition in a lubricating oil. When used in a lubricating oil in even very small amounts, i.e. in amounts as low as 0.1 Wt. percent and preferably not exceeding 20 wt. percent, the boron and amine-containing additive composition of our present invention overcomes the problems of the mineral lubricating oil in its use without additives by imparting to the lubricating oil high detergency properties and eliminating excessive varnish formation and corrosion, while suppressing octane requirement increase. The new composition may also be used in an additive concentrate in amounts of from to 50 weioht percent or more for addition to lubricating oils.

Broadly, our present invention provides an additive composition for lubricating oils formed by reacting a hydrolyzed phosphorus sulfide-hydrocarbon reaction prodami. e comthe resulting neutralized reaction product with boroph'osphoric acid. Our invention also provides an improved mineral oil containing an effective amount of our additive composition toimpart improved properties to the lubricating oil.

The amine compound used in preparing the additive composition of our present invention may be any aliphatic or substituted aliphatic compound having 1 or more basic amine groups. Preferred amine compounds particularly suited for use in the preparation of the additive composition of our present invention are the hydroxy aliphatic amines such as monohydroxy, dihydroxy, and

"ice

polyhydroxy aliphatic amines and particularly preferred are the aliphatic polyamines such as diamines, triamines, etc., having two or more carbon atoms in the alipha ic ohain. Polyhydroxy aliphatic polyamines are includable in either group. Particularly suitable aliphatic polyamines are ailkylene polyamines containing at least two primary amino nitrogen atoms. Examples of alkylene polyamines suitable for the hereindescribed purpose are ethylene diamine, propylene diamine, diethylene-triamine, diamylene triamine, triethylene tetramine, tripropylene tetramine, diethylene propylene tetramine, tetraethylene pcntamine, tetrabutylene pentamine, diethylendipropylcue pentamine, butylene diamine, dihexylene triamine, and the like, or mixtures thereof. For example, a suitable polyamine product is a crude diethylene triamine containing minor amounts :of ethylene diamine and triethylene tetramine. Other suitable aliphatic polyamines include those having the general formula nnmcnpmn,

in which R is preferably a C to C aliphatic chain, and which are obtained by condensing the suitable amine with acrylonitrile and hydrogenating to the corresponding diamine. Commercially available aliphatic polyamines of this type are those marketed by Armour and Company as Duomeens, which are prepared by the condensation of a dodecyl (coco) amine or an octadecyl (tallow) amine with acrylonitrile followed by hydrogenation to the corresponding diamine product; these products are marketed as Du-omeen C and Duomeen T, respectively.

Borophosphoric acid, a dry nonhygroscopic powder, may be conveniently prepared by the method taught by L. H. Englund, US. Patent No. 2,375,638, issued May 8, 194-5.

The hydrolyzed phosphorus, sulfide-hydrocarbon reaction product may be prepared by any method known to the prior art. Vie prefer to react a hydrocarbon with from about 1% to about 50%, and preferably from about 5% to about 25% of phosphorus sulfide at .a temperature of from about 200 'F. to about 600 F. in a nonoxidizing atmosphere, as, for example, in a nitrogen atmosphere. The reaction is carried out for from about one to about ten hours or more, and preferably for about five hours. The reaction may be carried out in the presence of a sulfurizing agent such as sulfur, sulfur chlorides, etc., if desired. The product is hydrolyzed at a temperature of from about 200 F. to about 500 F., and preferably at a temperature of from about 220 F. to about 350 F. by hydrolyzing means, for example, by introducing steam through the reaction mixture. The hydrolyzed product may be solvent extracted to remove salts of inorganic phosphorus acids and low molecular weight organic phosphorus acids formed during hydrolysis. Solvent extraction may be accomplished in accordance with the method described by Norman E. Lemmon et al. in U.S. 2,843,579, issued luly 15, 1958.

In the phosphorus sulfide-hydrocarbon reaction used for preparing starting materials for the additive compositions of the present invention, any phosphorus sulfides such as P 5 P 8 P 8 or other phosphorus sulfides and preferably phosphorus pentasulide, P 5 may be reacted with a hydrocarbon.

The hydrocarbons used in the phosphorus sulfidehydrocarbon reaction may be polymers such as monooletin polymers, copolymers, graft polymers, etc. and may also be unpolymerized or unpolymerizable hydrocarbons such as olefins, parafiins, cycloparaflins, aromatic hydrocarbons, etc.

The mono-olefin polymer to be treated may be the polymer resulting from the polymerization of low molecular weight mono-olefins preferably the isomonoolefins, such as isobutylene and isoamylene and/or the copolymers obtained by the polymerization of hydrocarbon mixtures containing isomono-olefins and mono-olcfins of less than six carbon atoms and preferably those of four carbon atoms. The polymer may be obtained by the polymerization of these olefins or mixed olefins in the presence of catalysts such as sulfuric acid, phosphoric acid, or boron fluoride, aluminum chloride or other similar halide catalysts of the Friedel-Crafts type. The polymers advantageously have molecular weights ranging from about 150 to about 50,000 or more, and preferably from about 500 to about 10,000.

Various polymerized starting materials prepared by methods well known in the art may be used. For example, as a starting material there can be used the polymer or synthetic lubricating oil obtained by polymerizing the unsaturated hydrocarbons resulting from the vapor phase cracking of paraifin waxes in the presence of aluminum chloride which is fully described in U.S. patents Nos. 1,955,260; 1,970,402; and 2,091,398. Still another type of olefin polymer which may be employed is the polymer resulting from the treatment of vapor phase cracked gasoline and/or gasoline fractions with sulfuric acid or solid adsorbents, such as fullers earth, whereby the unsaturated polymerized hydrocarbons are removed. Also contempplated within the scope of this invention is the treatment with phosphorus sulfide of the polymers resulting from the voltolization of hydrocarbons as described for example in US. Patents Nos. 2,197,768 and 2,191,787.

Other hydrocarbons which we can use as reactants in the preparation of the phosphorus sulfide reaction product are paraflins, olefins, aromatics or alkyl aromatics, cyclic aliphatics, petroleum fractions, such as lubricating oil fractions, petrolatums, waxes, cracking cycle stocks, condensation products of the foregoing hydrocarbons, solvent extracts of petroleum extracts, etc.

The paraffin hydrocarbons can be those obtained from petroleum oils such as bright stock residuums, lubricating oil distillates, petrolatums, or paraffin waxes. We may also halogenate any of the foregoing parafiins and condense the same with aromatic hydrocarbons in the presence of anhydrous inorganic halides such as aluminum chloride, zinc chloride, boron fluoride and the like.

As examples of high molecular weight olefinic hydrocarbons which we may employ as reactants are cetene (C cerotene (C melene (C and mixed high molecular weight alkenes obtained by cracking petroleum oils.

Other preferred olefins suitable for the preparation of the herein described phosphorus sulfide reaction products are olefins having at least 20 carbon atoms in the molecule of which from about 13 carbon atoms to about 18 carbon atoms, md preferably at least 15 carbon atoms are in a long chain. Such olefins can be obtained by the dehydrogenation of parafiins, such as by the cracking of paraffin Waxes or by the dehalogena-tion of alkyl halides, preferably long chain alkyl halides, particularly halo genated parafiin waxes.

As further examples of starting material for the preparation of the hydrolyzed phosphorus sulfide-hydrocarbon reaction product, any of the hydrocarbons recited as useable by Norman E. Lernmon et al. in US. 2,843,579, issued July 15, 1958, may be employed herein.

More particularly, the additive composition concentrates of our present invention are formed by neutralizing a hydrolyzed phosphorus sulfide-hydrocarbon reaction product, formed, for example, as indicated above and preferably solvent extracted, with an amine compound having 2 or more carbon atoms and preferably an aliphatic polyamine as defined above. The neutralized product is then reacted with borophosphoric acid, preferably in amounts corresponding to from about 1 to about 3 moles boron per mole of neutralized product. We add up to about 1.1 moles of amine compound per mole of acid; phosphorus in the hydrolyzed reaction product depending on the type of amine compound used. It is preferred to neutralize only one amine group of a given amme compound and, therefore, from about 1 to about 1.1 moles of the amine compound per mole of acid phosphorus is preferred. No solvent is necessary, however, the borophosphoric acid reaction may be carried out in the resence of a suitable solvent for the borophosphoric acid such as alcohol, acetone, water, or other suitable solvent to increase solubility of the reactants. During the borophosphoric acid reaction, it may be advantageous to stir the mixture of neutralized reaction product and borophosphoric acid and to warm the mixture for a short period of time, for example about one hour, to increase the solubility of the borophosphoric acid. The reaction mixture is then heated to a temperature above C. to strip off water and allow the reaction to go to completion. We have found that when water is not stripped oif the reaction is reversible and will not go to completion due to the instability of the reaction product in the presence of water. During warming, the reaction mixture should not be heated to a temperature at which the amine is driven from the mixture. If temperatures higher than the boiling point of the amine are used means for retaining the amine, such as, for example, refluxing, should be employed. An alternative method of forming the boron and phosphorus-containing amine-neutralized reaction products which we have found acceptable is by first reacting the borophosphoric acid with the amine compound and then reacting the resulting product with the phosphorus sulfide-hydrocarbon reaction product.

After the water has been driven off and the reaction is completed, the reaction mixture is treated for removal of solvent by placing the mixture in a vacuum or by passing nitrogen gas or other inert gases through the reaction mixture at a temperature sufficient to strip solvent therefrom. One to six hours is generally sutficient to strip the solvent out; however, this period of time is dependent on the amount and temperature of the stripping gas used as well as the nature of the solvent. In the case where a lower boiling solvent such as acetone or methanol has been used it may be necessary to remove only traces of solvent by stripping with inert gas since much of the solvent will have been removed at the time water was driven from the mixture. The nitrogen blowing generally results in the formation of a clear product having dispersed impurities essentially removed. However, if the product should be hazy due to the presence of impurities, for example the presence of excess borophosphoric acid which has not reacted with the neutralized phosphorus sulfide hydrocarbon reaction product or has not dissolved therein, it may be desirable to filter the product through diatomaceous earth to obtain a suitably clear product. The products formed in the above reaction contain chemically bonded boron and phosphorus.

The additive composition, prepared in accordance with the preferred method set out above, may be used in lubricating oils in varying amounts constituting minor proportions of the total lubricating composition. The amount of additive used should be in excess of 0.1 weight percent. The additive is effective in imparting improved detergcncy to lubricating oils even when used in such small amounts as range from about 0.1 weight percent. However, it is preferred to add the additive composition to the lubricating oil in amounts of from about one Weight percent to about 10 weight percent although much greater amounts even above 15 weight percent may be advantageously employed.

HYDROLYZED INTERMEDIATE about five hours for product formation. The product had a phosphorus content of about 4.3% and a sulfur content of about 7.5%. The reaction product formed is then hydrolyzed with steam at a temperature of about 300 F. to about 400 F. The hydrolyzed product was diluted, for ease of handling, to about a 60% concentrate with a solvent extracted Mid-Continent mineral oil having a viscosity of about 38 SSU at 210 F. This product was used as a starting material for the preparation of additives in subsequent examples.

As a specific embodiment of our invention, the following example is given by way of illustration and is not intended as a limitation to the invention.

Example 2000 grams of the solvent extracted hydrolyzed intermediate were reacted with 73 grams (one mole per mole of intermediate) of ethylenediainine and a basic salt was formed. The basic salt was treated with 151 grams (1.22 moles per mole of intermediate) of borophosphoric acid with stirring at 100 C. for six hours. The reaction mixture was blown with nitrogen; 1255 grams of solvent extracted Mid-Continent 5 weight mineral oil having a viscosity of about 38 SSU at 210 F. were added and the mixture was filtered through Celite. The filtrate was a bright, brown, oil-soluble product which had a boron content of 0.16 Wt. percent, a nitrogen content of 0.58 wt. percent and a phosphorus content of 1.38 wt. percent.

The elfectiveness of the products of the present invention in improving the detergency characteristics of lubricating oils is demonstrated by the data in Table I. The data were obtained by subjecting a commercial-type lubricating oil with and without the product of the above example to the detergency and oxidation test known as the Squalene Indiana Stirring Oxidation Test (I.S.O.T.). In the Squalene I.S.O.T., by weight of squalene (a highly unsaturated reactive hydrocarbon that polymerizes easily and forms a tightly adhering varnish during the test) is added to the oil to be tested and the mixture is heated at 300 F. in a 500 cc. glass beaker in the presence of 5 square inches of copper and 10- square inches of iron. Four glass rods of 6 mm. diameter are suspended in the oil which is stirred at about 1300 rpm. by means of a glass stirrer. After 72 hours the test is ended and varnish values are determined. Varnish values or ratings are based upon visual inspection of the glass rods, in which a rod free of any varnish deposit is given a rating of 10 while a badly coated rod is given a rating of 1. Rods having appearances between these extremes are given intermediate values. The product of the above example was tested in 3.15% concentration in a commercial-type oil. The commercial-type oil used was a mixture of SW and 10W solvent extracted base stock containing a polyisobutylene polymer viscosity improver and having a viscosity of about 62 SSU at 210 F. having 0.75% by weight sulfurized dipentene corrosion inhibitor. A run was also made on the commercial-type oil Without the product additive prepared in the above example and the comparative results are shown in Table I, below.

TABLE I Varnish Additive: rating 3.15% by weight of the example 10 None 4 to 5 The herein described additive compositions of the present invention can be used as indicated above in varying amounts of from 0.1 up to about percent in lubricating oils. Although the present invention has been illustrated by the use of the additive compositions in mineral lubricating oils, it is not restricted thereto. Other lubricating oil bases can be used, such as hydrocarbon oils, both natural and synthetic, for example, those obtained by the polymerization of olefins, as well as synthetic lubricating oils of the alkylene oxide type and the polycarboxylic acid ester type, such as the oil soluble esters of adipic acid, sebacic acid, azelaic acid, etc. It is also contemplated that various other Well known additives, such as antioxidants, anti-foaming agents pourpoint depressors, extreme pressure agents, antiwear agents, may be incorporated in lubricating oils containing the additives of our invention.

Concentrates of a suitable oil base containing more than 10 percent, for example up to 50 percent or more, of the additives of this invention alone or in combination with other additives can be used for blending with hydrocarbon oils or other oils in the proportions desired for the particular conditions of use to give a finished lubricating product containing the additives of this invention.

Unless otherwise stated, the precentages given herein and in the claims are percentages by weight.

Although We have described our invention by reference to specific embodiments and examples thereof, such specific embodiments and examples as have been given are merely for the purpose of illustration of the invention and are not intended as limiting its scope. It is intended that modifications and variations of the present invention which are apparent from our foregoing description to those skilled in the art are to be considered within the scope of our present invention except as stated in the following appended claims.

We claim:

1. As a new composition of matter, an oil-soluble detergent neutralized reaction product prepared by the process comprising: reacting a phosphorus sulfide With a hydrocarbon; hydrolyzing the resulting phosphorus sulfidehydrocarbon reaction product; and reacting the hydrolyzed product with borophosphoric acid in an amount corresponding to from about one to about three moles of boron per mole of reaction product and with an aliphatic polya-rnine having from 2 to 21 carbon atoms in the aliphatic group in an amount corresponding to from about one to about 1.1 moles of polyarnine per mole of acid phosphorus, at a temperature below the temperature at which said polyarnine is driven "from the mixture of reactants.

2. A lubricating composition comprising a major amount of a hydrocarbon lubricating oil and from about 0.1 to about 20 weight percent of the composition of claim 1.

3. The composition of claim 1 wherein the aliphatic polyamine is ethylene diamine.

4. As a new composition of matter, an oil-soluble detergent neutralized reaction product prepared by the process comprising the steps of: reacting a phosphorus sulfide with a hydrocarbon; hydrolyzing the resultant phosphorus sulfide-hydrocarbon reaction product; neutralizing the hydrolyzed product with an aliphatic polyamine having from 2 to 21 carbon atoms in the aliphatic group in an amount corresponding to from about one to about 1.1 moles of polyamine per mole of acid phosphorus; and reacting the neutralize-d product with borophos-phoric acid in an amount corresponding to from about one to about three moles of boron per mole of reaction product at a temperature below the temperature at which said polyamine is driven from the mixture of reactants.

5. A lubricating composition comprising a major amount of hydrocarbon lubricating oil and from about 0.1 to about 20 weight percent of the composition of claim 4.

6. The composition of claim 4 wherein the aliphatic polyamine is ethylene diamine.

7. As a new composition of matter, an oil-soluble detergent neutralized reaction product prepared by the process comprising the steps of: reacting a phosphorus sulfide with a hydrocarbon; hydrolyzing the resultant phosphorus sulfide-hydrocarbon reaction product; reacting boro-phosphoric acid in an amount corresponding to from about one to about three moles of boron per mole of reaction product with an alkylene polyamine having from 2 to 21 carbon atoms in the alkylene group and containing at least two primary amino nitrogen atoms in an amount corresponding to from about one to about 1.1 moles of greases polyamine per mole of acid phosphorus; and reacting the resulting reaction product with the hydrolyzed phosphorus sulfide-hydrocarbon reaction product at a temperature below the temperature at which the polyaminc is driven from the mixture of reactants.

8. As a new composition of matter, an oil-soluble detergent neutralized reaction product prepared by the process comprising the steps of: reacting phosphorus sulfide with a hydrocarbon; hydrolyzing the resulting phosphorus sulfide-hydrocarbon reaction product; neutralizing the resulting hydrolyzed product with from about one to about 1.1 moles per mole of hydnolyzed reaction product of ethylene diamine; and reacting the resulting neutralized product with from about one to about three moles based on boron of borophosphoric acid per mole of neutralized product at a temperature below the temperature at Which the polyamine is driven from the mixture of reactants.

9. As a new composition of matter, an oil-soluble detergent neutralized reaction product prepared by the process comprising the steps of: reacting phosphorus sulfide with a butene polymer at a temperature of from about 200 to about 600 F.; hydrolyzing the resulting phosphorus sulfide-butene polymer reaction product; neutralizing the resulting hydrolyzed product with from about one to about 1.1 moles per mole of hydrolyzed reaction product of an alkylene polyamine having the formula wherein R is a C to C aliphatic hydrocarbon chain; reacting the resulting neutralized product With from about one to about three moles based on boron of borophosi2. phoric acid per mole of neutralized product at a temperature below the tempenature at which the polyamine is driven from the mixture of reactants; and heating the reactants to a temperature above 100 C. whereby water is stripped from the reaction mixture.

10. A lubricant additive concentrate consisting essentially of a mineral lubricating oil containing more than about 10% of an oil-soluble detergene neutralized reaction product prepared by the process comprising: reacting a phosphorus sulfide With a hydrocarbon; hydrolyzing the resulting phosphorus sulfide-hydrocarbon reaction product; and reacting the hydrolyzed product with borophosphoric acid in an amount corresponding to from about one to about three moles of boron per mole of reaction product and with an aliphatic polyamine having from 2 to 21 carbon atoms in the aliphatic group in an amount corresponding to from about one to about 1.1 moles of polyamine per mole of acid phosphorus, at a temperature beiow the tempenature at which the polyamine driven from the mixture of reactants.

References Cited in the file of this patent UNETED STATES PATENTS 2,053,474 Graves et al Sept. 8, 1936 2,160,917 Shoemaker et al June 6, 1939 2,346,156 Farrington et a1. Apr. 11, 1944 2,636,858 Jones et a1. Apr. 28, 1953 2,798,045 Buck et a1 July 2, 1957 2,809,934 Alford et al Oct. 15, 1957 2,900,376 Sabol et al. Aug. 18, 1959 

10. A LUBRICANT ADDITIVE CONCENTRATE CONSISTING ESSENTIALY OF A MINERAL LUBRICATING OIL CONTAINING MORE THAN ABOUT 10% OF AN OIL-SOLUBLE DETERGENT NEUTRALIZED REACTION PRODUCT PREPARED BY THE PROCESS COMPRISING: REACTING A PHOSPHOROUS SULFIDE WITH A HYDOCARBON; HYDROCARBON; HYDROLYING THE RESULTING PHOSPHORUS SULFIDE-HYDROCARBON REACTION PRODUCT; AND REACTING THE HYDROLYZED PRODUCT WITH BOROPHOSPHORIC ACID IN AN AMOUNT CORRESPONDING TO FROM ABOUT ONE TO ABOUT THREE MOLES OF BORON PER MOLE OF REACTION PRODUCT AND WITH AN ALIPHATIC POLYAMINE HAVING FROM 2 TO 21 CARBON ATOMS IN THE ALIPHATIC GROUP IN AN AMOUNT CORRESPONDING TO FROM ABOUT ONE TO ABOUT 1.1 MOLES OF POLYAMINE PER MOLE OF ACID PHOSPHORUS, AT A TEMPERATURE BELOW THE TEMPERATURE AT WHICH THE POLYAMINE IS DRIVEN FROM THE MIXTURE OF REACTANTS. 